// SPDX-License-Identifier: GPL-2.0
use crate::helpers::*;
use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
use std::fmt::Write;
fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
let group = expect_group(it);
assert_eq!(group.delimiter(), Delimiter::Bracket);
let mut values = Vec::new();
let mut it = group.stream().into_iter();
while let Some(val) = try_string(&mut it) {
assert!(val.is_ascii(), "Expected ASCII string");
values.push(val);
match it.next() {
Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),
None => break,
_ => panic!("Expected ',' or end of array"),
}
}
values
}
struct ModInfoBuilder<'a> {
module: &'a str,
counter: usize,
buffer: String,
}
impl<'a> ModInfoBuilder<'a> {
fn new(module: &'a str) -> Self {
ModInfoBuilder {
module,
counter: 0,
buffer: String::new(),
}
}
fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {
let string = if builtin {
// Built-in modules prefix their modinfo strings by `module.`.
format!(
"{module}.{field}={content}\0",
module = self.module,
field = field,
content = content
)
} else {
// Loadable modules' modinfo strings go as-is.
format!("{field}={content}\0", field = field, content = content)
};
write!(
&mut self.buffer,
"
{cfg}
#[doc(hidden)]
#[link_section = \".modinfo\"]
#[used]
pub static __{module}_{counter}: [u8; {length}] = *{string};
",
cfg = if builtin {
"#[cfg(not(MODULE))]"
} else {
"#[cfg(MODULE)]"
},
module = self.module.to_uppercase(),
counter = self.counter,
length = string.len(),
string = Literal::byte_string(string.as_bytes()),
)
.unwrap();
self.counter += 1;
}
fn emit_only_builtin(&mut self, field: &str, content: &str) {
self.emit_base(field, content, true)
}
fn emit_only_loadable(&mut self, field: &str, content: &str) {
self.emit_base(field, content, false)
}
fn emit(&mut self, field: &str, content: &str) {
self.emit_only_builtin(field, content);
self.emit_only_loadable(field, content);
}
}
#[derive(Debug, Default)]
struct ModuleInfo {
type_: String,
license: String,
name: String,
author: Option<String>,
description: Option<String>,
alias: Option<Vec<String>>,
firmware: Option<Vec<String>>,
}
impl ModuleInfo {
fn parse(it: &mut token_stream::IntoIter) -> Self {
let mut info = ModuleInfo::default();
const EXPECTED_KEYS: &[&str] = &[
"type",
"name",
"author",
"description",
"license",
"alias",
"firmware",
];
const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
let mut seen_keys = Vec::new();
loop {
let key = match it.next() {
Some(TokenTree::Ident(ident)) => ident.to_string(),
Some(_) => panic!("Expected Ident or end"),
None => break,
};
if seen_keys.contains(&key) {
panic!(
"Duplicated key \"{}\". Keys can only be specified once.",
key
);
}
assert_eq!(expect_punct(it), ':');
match key.as_str() {
"type" => info.type_ = expect_ident(it),
"name" => info.name = expect_string_ascii(it),
"author" => info.author = Some(expect_string(it)),
"description" => info.description = Some(expect_string(it)),
"license" => info.license = expect_string_ascii(it),
"alias" => info.alias = Some(expect_string_array(it)),
"firmware" => info.firmware = Some(expect_string_array(it)),
_ => panic!(
"Unknown key \"{}\". Valid keys are: {:?}.",
key, EXPECTED_KEYS
),
}
assert_eq!(expect_punct(it), ',');
seen_keys.push(key);
}
expect_end(it);
for key in REQUIRED_KEYS {
if !seen_keys.iter().any(|e| e == key) {
panic!("Missing required key \"{}\".", key);
}
}
let mut ordered_keys: Vec<&str> = Vec::new();
for key in EXPECTED_KEYS {
if seen_keys.iter().any(|e| e == key) {
ordered_keys.push(key);
}
}
if seen_keys != ordered_keys {
panic!(
"Keys are not ordered as expected. Order them like: {:?}.",
ordered_keys
);
}
info
}
}
pub(crate) fn module(ts: TokenStream) -> TokenStream {
let mut it = ts.into_iter();
let info = ModuleInfo::parse(&mut it);
let mut modinfo = ModInfoBuilder::new(info.name.as_ref());
if let Some(author) = info.author {
modinfo.emit("author", &author);
}
if let Some(description) = info.description {
modinfo.emit("description", &description);
}
modinfo.emit("license", &info.license);
if let Some(aliases) = info.alias {
for alias in aliases {
modinfo.emit("alias", &alias);
}
}
if let Some(firmware) = info.firmware {
for fw in firmware {
modinfo.emit("firmware", &fw);
}
}
// Built-in modules also export the `file` modinfo string.
let file =
std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
modinfo.emit_only_builtin("file", &file);
format!(
"
/// The module name.
///
/// Used by the printing macros, e.g. [`info!`].
const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
// SAFETY: `__this_module` is constructed by the kernel at load time and will not be
// freed until the module is unloaded.
#[cfg(MODULE)]
static THIS_MODULE: kernel::ThisModule = unsafe {{
kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _)
}};
#[cfg(not(MODULE))]
static THIS_MODULE: kernel::ThisModule = unsafe {{
kernel::ThisModule::from_ptr(core::ptr::null_mut())
}};
// Double nested modules, since then nobody can access the public items inside.
mod __module_init {{
mod __module_init {{
use super::super::{type_};
/// The \"Rust loadable module\" mark.
//
// This may be best done another way later on, e.g. as a new modinfo
// key or a new section. For the moment, keep it simple.
#[cfg(MODULE)]
#[doc(hidden)]
#[used]
static __IS_RUST_MODULE: () = ();
static mut __MOD: Option<{type_}> = None;
// Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
/// # Safety
///
/// This function must not be called after module initialization, because it may be
/// freed after that completes.
#[cfg(MODULE)]
#[doc(hidden)]
#[no_mangle]
#[link_section = \".init.text\"]
pub unsafe extern \"C\" fn init_module() -> core::ffi::c_int {{
// SAFETY: This function is inaccessible to the outside due to the double
// module wrapping it. It is called exactly once by the C side via its
// unique name.
unsafe {{ __init() }}
}}
#[cfg(MODULE)]
#[doc(hidden)]
#[no_mangle]
pub extern \"C\" fn cleanup_module() {{
// SAFETY:
// - This function is inaccessible to the outside due to the double
// module wrapping it. It is called exactly once by the C side via its
// unique name,
// - furthermore it is only called after `init_module` has returned `0`
// (which delegates to `__init`).
unsafe {{ __exit() }}
}}
// Built-in modules are initialized through an initcall pointer
// and the identifiers need to be unique.
#[cfg(not(MODULE))]
#[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
#[doc(hidden)]
#[link_section = \"{initcall_section}\"]
#[used]
pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init;
#[cfg(not(MODULE))]
#[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
core::arch::global_asm!(
r#\".section \"{initcall_section}\", \"a\"
__{name}_initcall:
.long __{name}_init - .
.previous
\"#
);
#[cfg(not(MODULE))]
#[doc(hidden)]
#[no_mangle]
pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{
// SAFETY: This function is inaccessible to the outside due to the double
// module wrapping it. It is called exactly once by the C side via its
// placement above in the initcall section.
unsafe {{ __init() }}
}}
#[cfg(not(MODULE))]
#[doc(hidden)]
#[no_mangle]
pub extern \"C\" fn __{name}_exit() {{
// SAFETY:
// - This function is inaccessible to the outside due to the double
// module wrapping it. It is called exactly once by the C side via its
// unique name,
// - furthermore it is only called after `__{name}_init` has returned `0`
// (which delegates to `__init`).
unsafe {{ __exit() }}
}}
/// # Safety
///
/// This function must only be called once.
unsafe fn __init() -> core::ffi::c_int {{
match <{type_} as kernel::Module>::init(&super::super::THIS_MODULE) {{
Ok(m) => {{
// SAFETY: No data race, since `__MOD` can only be accessed by this
// module and there only `__init` and `__exit` access it. These
// functions are only called once and `__exit` cannot be called
// before or during `__init`.
unsafe {{
__MOD = Some(m);
}}
return 0;
}}
Err(e) => {{
return e.to_errno();
}}
}}
}}
/// # Safety
///
/// This function must
/// - only be called once,
/// - be called after `__init` has been called and returned `0`.
unsafe fn __exit() {{
// SAFETY: No data race, since `__MOD` can only be accessed by this module
// and there only `__init` and `__exit` access it. These functions are only
// called once and `__init` was already called.
unsafe {{
// Invokes `drop()` on `__MOD`, which should be used for cleanup.
__MOD = None;
}}
}}
{modinfo}
}}
}}
",
type_ = info.type_,
name = info.name,
modinfo = modinfo.buffer,
initcall_section = ".initcall6.init"
)
.parse()
.expect("Error parsing formatted string into token stream.")
}
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